In electronic taximeters, it is usual to provide three to eight keys in order to control the various functions of the taximeter. Most electronic taximeters have three to four keys to release the various functions of the device. It has now become common, by virtue of the flexibility of microprocessing techniques, to equip taximeters with quite a number of additional functions which were previously not usual in mechanical taximeters, such as, e.g., sum formation, clearing of checking counter states (positions), etc. Accordingly, it is necessary when equipping the device with three to four control keys to make the releasing of the function dependent on the combined actuation of several keys. This means that the operation of the taximeter is made more difficult since it requires the taxi driver to refer to the operating instructions for releasing the special functions in order to determine which combination of keys will result in the release of a desired function.
It would be possible to simplify the operation of the device by means of the arrangement of a larger number of keys. This has also been done in various cases. However, in some cases, licensing regulations prohibit this, i.e., in various countries there are license regulations which state that the taximeters can only be brought into the individual function positions by means of a determined switching sequence.
It is already known, for example, from DE-OS 22 02 865 to equip taximeters with a large number of keys and to feed the key signals via a coder matrix to a register in which the actuated key coding remains stored until a new signal is given by means of the key.
The object of the present invention then is to provide an arrangement for controlling an electronic taximeter which makes it possible to furnish the device without great extra expenditure, with a smaller quantity of keys in which several functions can be assigned to each key under certain circumstances or with a very much greater quantity of keys, e.g., twice as great, each of which is then assigned preferably to only a single function.